Saturday, July 11, 2015

Extreme Weather

With an extreme cold snap hitting Melbourne this weekend, it seemed like a good time to have a look back at the outer limits of weather in our city. Melbourne people talk a lot about the weather, and we are nationally famous for the varied, 'four seasons in one day' nature of the local climate.

This list is a guide to some of our local weather records, and extreme weather events from the past 150 years:


HIGHEST TEMPERATURE


7 February, 2009: A day that will live in local infamy. A perfect nightmare of conditions - record high temperatures, low humidity and gale force, hot winds - triggered the worst bushfires in Australian history; half a dozen major conflagrations that claimed 173 lives and destroyed several regional communities.

In the week leading up to 'Black Saturday,' Victoria was hit by unusually high, sustained temperatures. In Melbourne, the maximum temperature climbed above 43 degrees on three consecutive days for the first time since record keeping began, in 1859. As the fires gained momentum on Saturday, the mercury reached 46.4 degrees; not only the hottest temperature ever recorded in Melbourne, but the the highest recorded in any major Australian city.

Fires burned out of control for two weeks, before being contained. The extreme weather, part of a longer heat wave, continued until the first week of March, when cooler conditions helped fire services finally extinguish the last of the blazes.



COLDEST TEMPERATURE

According to the Bureau of Meteorology, the coldest temperature recorded in Melbourne is - 2.8 degrees, registered on 21 July 1869.



SNOW IN MELBOURNE


This ranks as one of the great unanswered questions of Melbourne; does it ever snow in the city?

The answer, amazingly, is yes (but only very occasionally). While Mount Dandenong, and some of the other outer suburbs, gets a dusting every decade or so, the last snowfall in the CBD was in August 1951:


In Burwood, then schoolgirl Susan Webster (picture top) recalls the event:


There are also records of snow falling in the city in 1899.




HIGHEST WIND SPEED in CBD

The highest wind speed recorded in Melbourne was 121 km/hour, on 3 September 1982, at the anemometer in Olympic Park.



THE BRIGHTON TORNADO

On 2 February 1918, a hot, windy day produced an intense storm cell off the coast of Brighton, in Melbourne's south east. The storm was powerful enough to produce two tornadoes, which crossed the coast around 5.45pm. The effects were dramatic:




The last photo shows the Methodist church on Hawthorn Road, which had to be completely rebuilt Several dozen homes were also damaged, the roof torn off a local hotel, and the Sandringham rail line closed. A  number of people sustained minor injuries, and damages of 150 000 pounds incurred.

It is estimated that the windspeed of the tornadoes was between 250 and 320 km per hour, making this Melbourne's most violent storm.




HEAVIEST RAINFALL



The heaviest rainfall Melbourne has seen was recorded during a dramatic thunderstorm on February 3, 2005. 120mm fell in the 24 hours to 9am on February 4; a fifth of the city's average annual rainfall.

The storm was caused by a massive low pressure system off Victoria's south coast, so large that it extended right out into the Tasman Sea. Heavy rain continued throughout the following week, setting several more records for precipitation (highest 48 hour total, highest weekly total), and flooding was widespread.



THE GREAT FLOOD

The Yarra is a river prone to flooding. While this still occurs today during periods of heavy rain, a lot of planning and engineering effort has gone into minimising the effects in the inner city.

But this was not always the case.




On 13 July 1891, several days of sustained heavy rain caused the river to burst its banks in spectacular fashion, inundating the surrounding suburbs. The river would eventually swell to more than 300 metres in width:




Thousands of people were displaced by the flood, which took several days to subside.

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